HDAC1 and cancer: This is consistent with our previous transcriptome analysis performed with calvarial tissue from mice expressing miR‐34c from the Type I Collagen promoter (Col1a1 2.3kb‐miR‐34c), in which many cancer‐associated pathways including Notch signaling was dysregulated.(22) We also found that Direct p53 effectors, E2F transcription factor network, and Regulation of RB protein were differentially regulated, and genes associated in these pathways—E2F2, E2F5, HDAC1, BCL2, and CCNE2—were downregulated (Fig. 2F).